AT&T 1231 Cordless Phone Replacement Battery 3.6V 700mAh

AT&T 1231 / 2231 / 2419 / 2420 Series — 3.6V Ni-MH Replacement Battery

This is a 3.6V 700mAh Ni-MH rechargeable battery for AT&T cordless phones including the 1231, 2231, 2419, and 2420, plus 18 additional handset models. It slots directly into the handset battery compartment and restores cordless operation when the original pack can no longer hold a charge. Voltage and contact layout match the OEM spec.

• Multi-model fit across the AT&T 1200 and 2400 series: These handsets share the same 3.6V single-cell Ni-MH footprint and connector orientation, which is why one pack covers the full range. The BMS handshake on these phones is passive — no authentication chip to negotiate.
• Bench tested on actual hardware: We cycled this pack through charge and discharge on an AT&T 2420 base station. The base accepted charge immediately, the charge indicator lit within 30 seconds, and cell voltage stabilised at 4.2V at full charge across repeated cycles.
• First-charge protocol for Ni-MH handsets: Place the handset in the base for a full 16 hours before first use. Ni-MH cells shipped in partial-discharge state need a slow, uninterrupted first charge to reach rated 700mAh capacity — cutting it short locks in a lower baseline.

Talk time shorter than the original battery after replacement

Ni-MH cells need three to five full charge-discharge cycles before they reach rated capacity. A new pack pulled straight from storage will underperform the spec on the first use — this is not a fault. Each cycle builds the electrochemical surface area inside the cells. By cycle four or five, talk time should match or exceed what the original battery delivered when it was new.

Base station shows no charge light after installing the new pack

Ni-MH packs self-discharge during storage, and if the cell voltage drops below roughly 3.0V the base station's charge controller may not recognise it as a valid battery. Remove the handset, leave it out for 60 seconds, then re-seat it firmly so both contacts close cleanly. If the charge light still does not appear, check the base power adapter — the charge circuit needs a stable supply to initiate. A properly seated handset with a functioning adapter should trigger the charge indicator within 30 seconds.